CN111835118A

CN111835118A - Motor for vehicle

Info

Publication number: CN111835118A
Application number: CN202010301659.6A
Authority: CN
Inventors: 竹野元贵; 北川胜秀; 森正树; 竹内健登
Original assignee: Aisin AW Co Ltd; Toyota Motor Corp
Current assignee: Aisin AW Co Ltd; Toyota Motor Corp
Priority date: 2019-04-19
Filing date: 2020-04-16
Publication date: 2020-10-27
Anticipated expiration: 2040-04-16
Also published as: CN111835118B; EP3726706B1; JP2020178499A; EP3726706A1; US11444498B2; JP7231470B2; US20200336026A1

Abstract

The invention provides a motor for a vehicle, which can ensure the space of a cover side of a stator core and inhibit the inclination of the stator core on the cover side. A stator core (24) of a vehicle motor (10) is provided with bolt fastening portions (34a, 34b, 34c) which are respectively arranged in a protruding manner at a plurality of positions separated from each other in the circumferential direction (R) in an outer circumferential surface (24a) and are arranged to face the radial outer side of the stator core (24) and are penetrated in the axial direction by fastening bolts for fastening the stator core (24) to the bottom of a housing, a cover (14) of the vehicle motor (10) is provided with a plurality of convex portions (42a, 42b, 42c, 42d) which are arranged in a protruding manner from a plurality of positions surrounding the stator core (24) in an inner wall surface (14d) of the cover (14) and face the stator core (24), and the inclination of the stator core (24) in the direction (T) from a central axis (CL) to the bolt fastening portions (34a, 34b, 34c) is restrained.

Description

Motor for vehicle

Technical Field

The present invention relates to a motor for a vehicle, and more particularly, to a stator core support structure.

Background

There is known a vehicle motor including a bottomed cylindrical case, a cover combined with the case, a cylindrical stator core fixed to a bottom of the case and formed by laminating laminated steel plates in which a magnetic body such as iron or an iron alloy is plate-shaped, and a rotor rotatably supported in the stator core by the case and the cover. For example, patent document 1 discloses an electric motor (rotating electric machine) for a hybrid vehicle, which includes a housing (220), a cover (230), a stator core (141) formed by laminating plate-like magnetic bodies, fastened to the housing by fastening members (143), and supported by a cantilever, and a rotor (130), in paragraphs 0030 and 0040 and fig. 8. The housing of the motor of patent document 1 is provided with a small-diameter portion having a relatively small gap with the stator core. Further, in the paragraphs 0034 to 0036 and fig. 12 of patent document 1, in order to prevent the transmission of the vibration of the stator core (141) to the housing (220), it is described that the inner diameter of the large-diameter portion, that is, the inner diameter of the large-diameter portion is defined so that the large-diameter portion of the stator core and the large-diameter portion of the housing do not contact each other even when the inclination angle (θ) of the stator core is maximized.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open No. 2007 & 228725

Disclosure of Invention

Problems to be solved by the invention

However, in the motor as described above, it is considered that the inclination of the stator core is suppressed on the housing side by the small-diameter portion which extends over the entire circumference of the outer peripheral surface of the stator core. However, in order to suppress the inclination of the stator core on the cover side, there is a problem that it is difficult to dispose the coil terminal, the terminal of the neutral wire, or the like on the cover side of the stator core because the small-diameter portion which is close to the entire circumference is provided on the outer circumferential surface of the stator core on the cover side rather than on the case side.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle electric motor capable of suppressing the inclination of a stator core on an axial end side while securing a space on the axial end side of the stator core.

Means for solving the problems

A first aspect of the present invention is directed to a vehicle electric motor including: a cylindrical stator core formed by laminating a plurality of laminated steel sheets; a bottomed cylindrical case having an outer peripheral wall and accommodating one end portion of the stator core in an axial direction of the stator core; a bottomed cylindrical case cover having an outer peripheral wall, accommodating the other end portion of the stator core in the axial direction, and fixed to the case; a rotor supported within the stator core so as to be rotatable about a center axis of the stator core, the stator core has a plurality of bolt fastening portions that are provided so as to protrude toward the outside in the radial direction of the stator core at a plurality of positions that are circumferentially spaced from each other in the outer peripheral surface of the stator core, and is penetrated in the axial direction by a fastening bolt for fastening the stator core to the bottom of either the housing or the housing cover, the other of the housing and the housing cover has a plurality of protrusions protruding toward the stator core from a plurality of positions surrounding the stator core on an inner wall surface of the other, and the inclination of the stator core in the direction from the central axis toward the bolt fastening portion is suppressed. Further, for example, the plurality of projections include at least two projections each disposed so as to be adjacent to a corresponding one of the plurality of bolt fastening portions, and a distance in the circumferential direction between each of the at least two projections and the corresponding one of the bolt fastening portions is set to a value equal to or smaller than one third of an angular interval between the corresponding one of the bolt fastening portions and another bolt fastening portion adjacent to each other in the circumferential direction. Here, "adjacent" includes not only a case where each of the at least two projections abuts on the corresponding one of the bolt fastening portions in the circumferential direction, but also a case where the projections abut and face each other in the radial direction. For example, one of the housing and the housing cover is the housing, and the other of the housing and the housing cover is the housing cover.

A second aspect of the present invention is the first aspect of the present invention, wherein the convex portion is provided on an inner wall surface of the other of the housing and the housing cover within an angular range adjacent to the bolt fastening portion, the angular range being an angular range obtained by trisecting an interval between two adjacent bolt fastening portions among the plurality of bolt fastening portions in the circumferential direction.

A third aspect of the present invention is the bolt fastening device according to the first or second aspect, wherein the plurality of protruding portions are provided at positions where respective distal ends of the plurality of protruding portions come into contact with a position closer to the bolt fastening portion side than the intermediate position in the circumferential direction between two adjacent bolt fastening portions of the plurality of bolt fastening portions.

A fourth aspect of the present invention is the stator core of any one of the first to third aspects of the present invention, wherein at least one of the convex portions for suppressing the inclination of the stator core in one direction is provided in each of a plurality of directions from the central axis toward the plurality of bolt fastening portions.

A fifth aspect of the present invention is the electric motor according to any one of the first to fourth aspects of the present invention, wherein a pair of the projections are provided so as to project from an inner wall surface of the other of the housing and the housing cover so as to sandwich the bolt fastening portion from both sides in the circumferential direction, and the pair of projections are provided at positions symmetrical to each other in the circumferential direction with respect to the bolt fastening portion.

A sixth aspect of the present invention is the stator core of any one of the first to fourth aspects of the present invention, wherein the pair of the protruding portions are provided so as to protrude from an inner wall surface of the other of the housing and the housing cover facing an outer peripheral surface of the stator core between two adjacent bolt fastening portions of the plurality of bolt fastening portions, and are provided at positions symmetrical to each other with respect to a line connecting a circumferential intermediate position between the two adjacent bolt fastening portions and the central axis.

A seventh aspect of the invention is directed to any one of the first to fourth aspects of the invention, wherein the plurality of convex portions suppress the inclination of the stator core by a tip end of each of the plurality of convex portions coming into contact with any one of the plurality of bolt fastening portions.

Effects of the invention

According to a first aspect of the present invention, there is provided a vehicle electric motor comprising: a cylindrical stator core formed by laminating a plurality of laminated steel sheets; a bottomed cylindrical case having an outer peripheral wall and accommodating one end portion of the stator core in an axial direction of the stator core; a bottomed cylindrical case cover having an outer peripheral wall, accommodating the other end portion of the stator core in the axial direction, and fixed to the case; a rotor supported within the stator core so as to be rotatable about a center axis of the stator core, the stator core has a plurality of bolt fastening portions that are provided so as to protrude toward the outside in the radial direction of the stator core at a plurality of positions that are circumferentially spaced from each other in the outer peripheral surface of the stator core, and is penetrated in the axial direction by a fastening bolt for fastening the stator core to the bottom of either the housing or the housing cover, the other of the housing and the housing cover has a plurality of protrusions protruding toward the stator core from a plurality of positions surrounding the stator core on an inner wall surface of the other, and the inclination of the stator core in the direction from the central axis toward the bolt fastening portion is suppressed. In this case, the plurality of convex portions can effectively suppress the inclination of the stator core in the direction from the central axis toward the bolt fastening portion to which the axial force of the fastening bolt is applied, which tends to largely incline. Further, instead of providing the other of the housing and the housing cover with a projection portion that is entirely close to the outer peripheral surface of the stator core, the plurality of projection portions can be efficiently arranged, so that a space on the cover side of the stator core can be secured, and a high degree of freedom can be secured with respect to the arrangement of the coil terminals of the stator coil, the terminals of the neutral wire, and the like.

According to the vehicle electric motor of the second aspect of the invention, the convex portion is provided on the inner wall surface of the other of the case and the case cover within the angular range adjacent to the bolt fastening portion out of the angular range obtained by trisecting the interval between two adjacent bolt fastening portions among the plurality of bolt fastening portions in the circumferential direction. In this way, the projection can effectively suppress the stator core from falling down in the direction of the bolt fastening portion to which the axial force of the fastening bolt is applied.

According to the vehicle electric motor of the third aspect of the invention, the plurality of protruding portions are provided at positions where the tip ends of the plurality of protruding portions come into contact with the bolt fastening portion side of the intermediate position in the circumferential direction between two adjacent bolt fastening portions of the plurality of bolt fastening portions. In this way, the plurality of protrusions can effectively suppress the stator core from falling in the direction of the bolt fastening portion to which the axial force of the fastening bolt is applied. In addition, while a space on the cover side of the stator core is secured, a high degree of freedom can be secured with respect to the arrangement of terminals such as coil terminals of the stator coil and terminals of the neutral wire.

According to the vehicle electric motor of the fourth aspect of the invention, at least one of the convex portions that suppresses the inclination of the stator core in one direction is provided in each of the plurality of directions from the central axis toward the plurality of bolt fastening portions. In this way, the projection can effectively suppress the stator core from falling down in the direction of the bolt fastening portion to which the axial force of the fastening bolt is applied.

In the vehicle electric motor according to the fifth aspect of the invention, the pair of protrusions are provided so as to protrude from the inner wall surface of the other of the case and the case cover so as to sandwich the bolt fastening portion from both sides in the circumferential direction, and the pair of protrusions are provided at positions symmetrical to each other in the circumferential direction with respect to the bolt fastening portion. In this way, the inclination of the stator core in the direction of the bolt fastening portion to which the axial force of the fastening bolt is applied can be effectively suppressed by the pair of convex portions.

In the vehicle electric motor according to the sixth aspect of the invention, the pair of the protruding portions are provided so as to protrude from the inner wall surface of the other of the housing and the housing cover that faces the outer peripheral surface of the stator core between two adjacent bolt fastening portions among the plurality of bolt fastening portions, and are provided at positions that are symmetrical to each other with respect to a line that connects the circumferential intermediate position and the center axis between the two adjacent bolt fastening portions. In this way, the inclination of the stator core in the direction of the bolt fastening portion to which the axial force of the fastening bolt is applied can be effectively suppressed by the pair of convex portions.

According to the vehicle electric motor of the seventh aspect of the invention, the plurality of protruding portions suppress the inclination of the stator core by the tip ends of the plurality of protruding portions coming into contact with any one of the plurality of bolt fastening portions. In this way, the projection can effectively suppress the stator core from falling down in the direction of the bolt fastening portion to which the axial force of the fastening bolt is applied.

Drawings

Fig. 1 is a diagram schematically showing a vehicle electric motor to which the present invention is applied, and is a vertical cross-sectional view including a rotation center line of a rotor of the vehicle electric motor.

Fig. 2 is a view schematically showing a state in which a stator core of the vehicle motor of fig. 1 is tilted.

Fig. 3 is a cross-sectional view of the vehicle electric motor, which corresponds to a cross-sectional view taken along line III-III of fig. 1 as a schematic diagram.

Fig. 4 is an enlarged and shown longitudinal sectional view of a part of the section taken along line IV-IV of fig. 3.

Fig. 5 is a view showing a vehicle electric motor according to another embodiment of the present invention, and corresponds to fig. 3.

Fig. 6 is a diagram illustrating a vehicle electric motor according to another embodiment of the present invention, and corresponds to fig. 3.

Fig. 7 is a longitudinal sectional view showing a section along line VII-VII of fig. 6.

Fig. 8 is a diagram illustrating a vehicle electric motor according to another embodiment of the present invention, and corresponds to fig. 3.

Fig. 9 is a diagram showing a cross-sectional view of a vehicle electric motor of a comparative example having no convex portion on the lid side.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, the drawings are simplified or modified as appropriate for the purpose of explanation, and the dimensional ratios, shapes, and the like of the respective portions are not necessarily drawn accurately.

[ example 1 ]

Fig. 1 is a schematic view showing a vehicle electric motor (hereinafter, referred to as an electric motor) 10 as an embodiment of the present invention, and is a vertical cross-sectional view including a center axis CL as a rotation center line of a rotor 12. The motor 10 includes a housing cover (hereinafter referred to as a cover) 14, a housing 16, a rotor 12, and a stator core 24 around which a stator coil 22 is wound. The lid 14 is in a bottomed cylindrical shape, and has an outer peripheral wall 14a and a bottom 14b, and a bearing 28 is fitted in a bearing fitting hole provided in the bottom 14b of the lid 14. The housing 16 is in a bottomed cylindrical shape and has an outer peripheral wall 16a and a bottom 16b, and a bearing 30 is fitted in a bearing fitting hole provided in the bottom 16b of the housing 16.

A cylindrical stator core 24 in which a plurality of laminated steel plates 32 electrically insulated from each other by an oxide film are laminated is housed inside the cover 14 and the case 16. The outer peripheral surface 24a of the stator core 24 and the inner wall surface 14d of the outer peripheral wall 14a of the cover 14 are spaced apart from each other so as to have a gap S in the radial direction of the motor 10, that is, in the radial direction of the stator core 24. At a plurality of positions spaced apart from each other in the circumferential direction R (see fig. 3) of the cylindrical stator core 24 in the outer circumferential surface 24a of the stator core 24, bolt fastening portions 34 are provided so as to protrude outward of the stator core 24. Since the bolt fastening portion 34 is inserted in the axial direction of the motor 10, that is, the axial direction of the stator core 24 by the fastening bolt 38, the stator core 24 is fastened to the bottom portion 16b of the housing 16. In the present embodiment, as will be described later, three bolt fastening portions 34 are provided at equal intervals of 120 ° on the outer peripheral surface 24a of the stator core 24 (see fig. 3).

The cover 14 and the case 16 are fixed to each other by fastening a plurality of bolts, not shown, and the stator core 24 is housed inside the cover 14 and the case 16 such that one end portion 24b of the stator core 24 in the axial direction of the motor 10 is housed inside the case 16 and the other end portion 24c is housed inside the cover 14. A mating surface 14c is provided at the tip of the outer peripheral wall 14a of the cover 14, and a mating surface 16c is provided at the tip of the outer peripheral wall 16a of the case 16. When the cover 14 and the housing 16 are fixed to each other, the combining

surfaces

14c and 16c are in surface contact with each other in the radial direction of the motor 10 at a position overlapping the stator core 24 and are fixed. As shown in fig. 1, the radial direction is a direction perpendicular to the central axis CL, and the axial direction is a direction parallel to the central axis CL.

In a space E1 between the case 16 and the one end 24b of the stator core 24 and a space E2 between the cover 14 and the other end 24c of the stator core 24, the coil end 22a of the stator coil 22 is disposed, and the terminal 40 such as a coil terminal or a neutral terminal is disposed in a space E2 between the cover 14 and the other end 24c of the stator core 24.

The rotor 12 is housed inside the cylindrical stator core 24 such that the center axis CL of the rotor 12 and the center axis CL of the inner circumferential surface 24d of the stator core 24 are concentric with each other, and the rotor 12 is supported by the cover 14 and the housing 16 via the bearing 28 and the bearing 30 so as to be rotatable about the center axis CL of the rotor 12. The motor 10 configured as described above is, for example, an ac synchronous motor, and when a rotating magnetic field is formed by a three-phase ac current supplied to the stator coil 22, the rotor 12 incorporating a permanent magnet is rotationally driven in accordance with the rotating magnetic field. The other end 24c of the stator core 24 is not fixed to either the cover 14 or the housing 16. That is, the stator core 24 is supported only on one side so that only the one end portion 24b on the case 16 side is fixed to the bottom portion 16b of the case 16.

The lid 14 is provided with a plurality of projections 42 projecting from the inner wall surface 14d of the lid 14 toward the outer peripheral surface 24a of the stator core 24. In the present embodiment, as described later, four

convex portions

42a, 42b, 42c, and 42d (hereinafter, simply referred to as convex portions 42 when a plurality of convex portions are not particularly distinguished) are provided so as to protrude from an inner wall surface 14d of the lid 14 (see fig. 3).

Further, the housing 16 is formed with a stator core positioning portion 44, which is a convex portion of the housing 16 protruding from the inner wall surface 16d of the housing 16 toward the outer peripheral surface 24a of the stator core 24. The stator core positioning portion 44 is a circumferentially continuous convex portion for positioning the one end portion 24b of the stator core 24 and the bottom portion 16b of the housing 16 before the stator core 24 is fastened to the housing 16 by the plurality of fastening bolts 38.

Fig. 2 is a schematic diagram showing a state in which the stator core 24 of the motor 10 is tilted. As shown in fig. 2, when the stator core 24 is largely tilted, the outer peripheral surface 24a of the stator core 24 contacts the convex portion 42 provided on the lid 14, and therefore, the tilting of the stator core 24 is suppressed.

Returning to fig. 1, in the radial direction, a distance L1 between the convex portion 42 and the outer circumferential surface 24a of the stator core 24 when the stator core 24 is not tilted is set shorter than a distance L2 between the inner wall surface 14d of the lid 14 and the outer circumferential surface 24a of the stator core 24. In the radial direction, the distance L1 between the convex portion 42 and the outer circumferential surface 24a of the stator core 24 when the stator core 24 is not tilted is set to be shorter than the distance L3 between the inner circumferential surface 24d of the stator core 24 and the outer circumferential surface 12a of the rotor 12 when the stator core 24 is not tilted.

Fig. 3 is a cross-sectional view of the motor 10, which corresponds to a cross-sectional view taken along line III-III of fig. 1 as a schematic view, and fig. 4 is a longitudinal sectional view showing a part of a cross-sectional view taken along line IV-IV of fig. 3 in an enlarged manner. In fig. 3 and 4, the rotor 12 and the fastening bolt 38 are omitted. As shown in fig. 3, three

bolt fastening portions

34a, 34b, 34c (hereinafter, simply referred to as bolt fastening portions 34 in the case where the three bolt fastening portions are not particularly distinguished) are provided on the outer peripheral surface 24a of the stator core 24 around the center axis CL at equal intervals of an angle of 120 °. The plurality of

projections

42a, 42b, 42c, and 42d provided on the cover 14 are provided so as to project toward the stator core 24 from a plurality of positions surrounding the stator core 24 in the inner wall surface 14d of the cover 14.

The

convex portions

42a, 42b, and 42c of the plurality of

convex portions

42a, 42b, 42c, and 42d are provided at positions adjacent to the bolt fastening portion 34. Specifically, as shown in fig. 3, the inner wall surface 14d in the angular range M1 is provided with the

convex portions

42a, 42b, and 42c, wherein the angular range M1 is an angular range adjacent to the bolt fastening portion 34 in a range of angles (hereinafter, referred to as an angular range) obtained by trisecting the interval between the adjacent bolt fastening portions 34 in the circumferential direction R among the bolt fastening portions 34 provided on the outer circumferential surface 24a of the stator core 24 at equal intervals of an angle 120 °, in other words, the angular range M1 is an angular range adjacent to the bolt fastening portion 34 in a range of angles 40 ° obtained by trisecting the angle 120 ° of the adjacent bolt fastening portions 34. That is, the

convex portions

42a, 42b, and 42c are provided on the inner wall surface 14d of the range (i.e., the angle range M1) adjacent to the bolt fastening portion 34 at an angle of 40 ° with respect to a line passing between the center of the hole of the bolt fastening portion 34 through which the bolt passes and the center axis CL.

As shown in fig. 3, the

convex portions

42a, 42b, and 42c are provided on the inner wall surface 14d so that at least a part of each of the

convex portions

42a, 42b, and 42c is located in an angle range M2, where the angle range M2 is an angle range adjacent to the bolt fastening portion 34, out of an angle range obtained by dividing the interval between adjacent bolt fastening portions 34 by six times in the circumferential direction R. That is, in the present embodiment, at least a part of each of the

convex portions

42a, 42b, and 42c is disposed in a range (i.e., an angle range M2) adjacent to the bolt fastening portion 34 at an angle of 20 ° from the bolt fastening portion 34.

T shown in fig. 3 is a direction from the center axis CL toward the bolt fastening portion 34b, and representatively shows one of three directions toward the three

bolt fastening portions

34a, 34b, 34 c. The convex portion 42a is provided so as to protrude from the inner wall surface 14d of the cover 14 so as to suppress the inclination of the stator core 24 in the direction T from the center axis CL toward the bolt fastening portion 34a, the convex portion 42b is provided so as to protrude from the inner wall surface 14d of the cover 14 so as to suppress the inclination of the stator core 24 in the direction T from the center axis CL toward the bolt fastening portion 34b, and the convex portion 42c and the convex portion 42b are provided so as to protrude from the inner wall surface 14d of the cover 14 so as to suppress the inclination of the stator core 24 in the direction T from the center axis CL toward the bolt fastening portion 34 c. The

convex portions

42a, 42b, 42c, and 42d are not provided at positions where the tips of the

convex portions

42a, 42b, 42c, and 42d contact the intermediate position N in the circumferential direction R between the bolt fastening portions 34.

In addition, as shown in fig. 4, in order to secure the insulation gap Z, a plurality of protrusions 42 are not provided at the inner wall surface 14d facing the outer peripheral surface of the coil end 22a, and the protrusions 42 are provided on the inner wall surface 14d facing the stator core 24 in the axial direction. The shape of the coil end 22a varies over the entire circumference according to the winding method of the coil, and a part thereof may exceed the outer diameter of the stator core 24. Therefore, there may also be a case where the required insulation distance between the coil end 22a and the cover 14 is larger than the required insulation distance between the stator core 24 and the cover 14. However, in the present embodiment, since the convex portion 42 is not provided on the inner wall surface 14d facing the outer peripheral surface of the coil end 22a, the insulation gap Z between the coil end 22a and the cover 14 can be sufficiently ensured.

Fig. 9 is a diagram showing a state in which the stator core 24 is tilted in the motor 510 of the comparative example including the cover 514 not provided with the convex portion 42. As shown in fig. 9, the stator core 24 of the motor 510 is directly fixed to the bottom of the housing 516 by a plurality of fastening bolts 38, but is not directly fixed to the cover 514. Therefore, when the motor 510 is installed on a vehicle or the like with the center axis CL of the motor 510 oriented in the horizontal direction, that is, when the motor 510 is horizontally placed, the stator core 24 is supported only by the case 516, and therefore, the stator core 24 may be inclined. Further, the stator core 24 may be bent when the motor 510 is oscillated or when the electromagnetic force is large due to vibration caused by an external force such as vibration or impact applied during traveling of the vehicle, and the stator core 24 may be inclined. For example, when these inclinations are combined, the stator core 24 is excessively inclined, and particularly, the inner peripheral surface of the stator core 24 is close to the cover-side outer peripheral surface of the rotor 12 on the cover 514 side, and there is a possibility that the stator core 24 and the rotor 12 are excessively close to each other or interfere with each other.

When the stator core 24 is long in the center axis CL direction, when the diameter of the stator core 24 is small, or when the length of the stator core positioning portion 544 provided inside the housing 516 in the center axis CL direction is short, the stator core 24 is likely to be inclined. When the stator core 24 is fastened to the case 516 by the plurality of fastening bolts 38, the stator core 24 is likely to be inclined in the direction of the bolt fastening portion 534 of the stator core 24 due to a force at the time of fastening or assembling, a variation in thickness of the laminated steel plates, and the like.

However, in the present embodiment, as shown in fig. 1, the distance L1 between the convex portion 42 of the cover 14 and the outer peripheral surface 24a of the stator core 24 is set shorter than the distance L3 between the inner peripheral surface 24d of the stator core 24 and the outer peripheral surface 12a of the rotor 12. Therefore, the outer peripheral surface 24a of the stator core 24 contacts the convex portion 42 before the inner peripheral surface 24d of the stator core 24 contacts the outer peripheral surface 12a of the rotor 12, and therefore, the inclination of the stator core 24 can be suppressed, and the possibility of interference between the stator core 24 and the rotor 12 can be reduced.

In a space E2 between the cover 14 and the other end 24c of the stator core 24, a coil end 22a, a terminal 40 such as a coil terminal or a neutral terminal, and the like are arranged. Therefore, when the convex portion 42 is provided over the entire circumference of the inner wall surface 14d of the cover 14 in order to suppress the inclination of the stator core 24 in all directions, the space E2 becomes narrow, and it becomes difficult to dispose the terminal 40. However, in the present embodiment, the convex portions are not provided over the entire circumference of the inner wall surface 14d of the cover 14, but as shown in fig. 3, the plurality of convex portions 42 suppress the falling of the stator core 24. The plurality of convex portions 42 are provided so as to suppress the stator core 24 from falling down in the direction T from the center axis CL toward the bolt fastening portion 34. Therefore, the falling of the stator core 24 is suppressed while the space E2 on the lid 14 side of the stator core 24 is ensured.

As described above, according to the electric motor 10 of the present embodiment, the electric motor 10 for a vehicle includes: a cylindrical stator core 24 formed by laminating a plurality of laminated steel sheets 32; a bottomed cylindrical case 16 having an outer peripheral wall 16a and accommodating one end portion 24b of the stator core 24 in an axial direction thereof; a bottomed cylindrical cover 14 having an outer peripheral wall 14a, housing the other end 24c of the stator core 24 in the axial direction, and fixed to the case 16; and a rotor 12 supported rotatably about a center axis CL of the stator core within the stator core 24, wherein the stator core 24 includes bolt fastening portions 34, the bolt fastening portions 34 are provided so as to protrude outward in a radial direction of the stator core 24 at a plurality of positions spaced apart from each other in a circumferential direction R in an outer circumferential surface 24a of the stator core 24, and are penetrated in the axial direction by fastening bolts 38 that fasten the stator core 24 to a bottom portion 16b of the housing 16, and the cover 14 includes a plurality of protrusions 42, the plurality of protrusions 42 are provided so as to protrude toward the stator core 24 from a plurality of positions on an inner wall surface 14d of the cover 14 that surround the stator core 24, and suppress a fall of the stator core 24 in a direction T from the center axis CL toward the bolt fastening portions 34.

In this way, the plurality of convex portions 42 can effectively suppress the inclination of the stator core 24 in which the laminated steel plates 32 are laminated in the direction T of the bolt fastening portion 34 to which the axial force of the fastening bolt 38 is applied, which tends to largely incline. Further, instead of providing the lid 14 with the convex portions 42 that are close to each other over the entire circumference of the outer circumferential surface 24a of the stator core 24, the plurality of convex portions 42 can be effectively arranged, so that the space E2 on the lid 14 side of the stator core 24 can be ensured, and a high degree of freedom can be ensured in the arrangement of the coil terminals of the stator coil 22, the terminals of the neutral wire, and the like.

Further, according to the electric motor 10 of the present embodiment, the convex portion is provided on the inner wall surface 14d of the cover 14 in the angular range M1, wherein the angular range M1 is an angular range adjacent to the bolt fastening portion 34, out of an angular range obtained by trisecting the interval between two adjacent bolt fastening portions 34 in the plurality of bolt fastening portions 34 in the circumferential direction R. In this way, the

protrusions

42a, 42b, and 42c can effectively suppress the stator core 24 from falling in the direction T of the bolt fastening portion 34 to which the axial force of the fastening bolt 38 is applied.

Further, according to the electric motor 10 of the present embodiment, at least one convex portion 42 that suppresses the inclination of the stator core 24 in one direction is provided with respect to each of the plurality of directions T from the center axis CL toward each of the plurality of bolt fastening portions 34. In this way, the

protrusions

Further, according to the motor 10 of the present embodiment, the convex portion 42 is not provided at a position where the tip of the convex portion 42 contacts the intermediate position N in the circumferential direction R between the adjacent bolt fastening portions 34. In other words, the plurality of projections 42 are provided at positions where the tips of the plurality of projections 42 contact the bolt fastening portion 34 side with respect to the intermediate position N in the circumferential direction R between two adjacent bolt fastening portions 34 of the plurality of bolt fastening portions 34. In this way, the plurality of protrusions 42 can effectively suppress the stator core 24 from falling in the direction T of the bolt fastening portion 34 to which the axial force of the fastening bolt 38 is applied. Further, a space on the cover 14 side of the stator core 24 can be secured, and a high degree of freedom can be secured with respect to the arrangement of the terminals 40 such as the coil terminals of the stator coil 22 and the terminals of the neutral wire.

[ example 2 ]

Next, another embodiment of the present invention will be explained. In the following description, the same reference numerals are used for the common portions of the embodiments, and the description thereof will be omitted.

Fig. 5 is a view showing a motor 210 according to another embodiment of the present invention, and corresponds to fig. 3. In the present embodiment, three pairs of

convex portions

242a, 243a, 242b, 243b, 242c, and 243c (hereinafter, simply referred to as the convex portions 242 and 243 when the convex portions are not particularly distinguished) are provided so as to protrude from a plurality of positions on the inner wall surface 14d of the cover 14 surrounding the stator core 24 toward the stator core 24. The three pairs of protruding portions 242 and 243 are provided at positions adjacent to the bolt fastening portions 34, specifically, inside an angular range M2 adjacent to the bolt fastening portions 34, out of angular ranges obtained by dividing the interval between adjacent bolt fastening portions 34 on the inner wall surface of the cover 14 by six in the circumferential direction R. That is, in the present embodiment, the convex portions 242 and 243 are provided inside the range of the angle of ± 20 ° from the bolt fastening portion 34.

The pair of

projections

242a, 243a are provided to project from the inner wall surface 14d so as to sandwich the bolt fastening portion 34a from both sides in the circumferential direction R, and the pair of

projections

242a, 243a are provided at positions symmetrical to each other in the circumferential direction R with respect to the bolt fastening portion 34 a. As shown in fig. 5, the pair of

convex portions

242b and 243b and the pair of

convex portions

242c and 243c are also provided so as to protrude from the inner wall surface 14d so as to sandwich the

bolt fastening portion

34b or 34c from both sides in the circumferential direction R, and are provided at positions symmetrical to each other in the circumferential direction R with respect to the

bolt fastening portion

34b or 34c, similarly to the pair of

convex portions

242a and 243a, respectively. That is, a pair of convex portions 242 and 243 for suppressing the inclination of the stator core 24 in one direction is provided in each of the directions T from the center axis CL toward the bolt fastening portion 34.

The

convex portions

243a and 242b are provided between the bolt fastening portion 34a and the bolt fastening portion 34 b. Specifically, the pair of protruding

portions

243a and 242b protrude from the inner wall surface 14d facing the outer peripheral surface 24a of the stator core 24 between the two adjacent

bolt fastening portions

34a and 34 b. The

convex portions

243a and 242b are provided at positions symmetrical to each other with respect to a line connecting a center position N in the circumferential direction R between the

bolt fastening portions

34a and 34b and the center axis CL. As shown in fig. 5, the pair of

convex portions

243b and 242c and the pair of

convex portions

243c and 242a are also similar to the pair of

convex portions

243a and 242 b.

As described above, according to the motor 210 of the present embodiment, the pair of convex portions 242 and 243 are provided to protrude from the inner wall surface 14d of the cover 14 so as to sandwich the bolt fastening portion 34 from both sides in the circumferential direction R, and are provided at positions symmetrical to each other in the circumferential direction R with respect to the bolt fastening portion 34. In this way, the pair of convex portions 242 and 243 effectively suppress the stator core 24 from falling in the direction T of the bolt fastening portion 34 to which the axial force of the fastening bolt 38 is applied.

Further, according to the motor 210 of the present embodiment, the pair of convex portions 242 and 243 are provided so as to protrude from the inner wall surface 14d of the cover 14 facing the outer peripheral surface 24a of the stator core 24 between two adjacent bolt fastening portions 34 out of the plurality of bolt fastening portions 34, and are provided at positions symmetrical to each other with respect to a line connecting the center position N in the circumferential direction R between the two adjacent bolt fastening portions 34 and the center axis CL. In this way, the pair of convex portions 242 and 243 can effectively suppress the inclination of the stator core 24 in the direction T of the bolt fastening portion 34 to which the axial force toward the fastening bolt 38 is applied.

[ example 3 ]

Fig. 6 is a view showing a motor 310 according to another embodiment of the present invention, which corresponds to fig. 3, and fig. 7 is a longitudinal sectional view showing a section taken along line VII-VII in fig. 6. In fig. 7, the rotor 12 and the

bearings

28 and 30 are omitted. In the present embodiment, a plurality of

projections

342a, 342b, 342c (hereinafter, simply referred to as projections 342 when the projections are not particularly distinguished) provided on the inner wall surface 14d of the cover 14 are provided to project toward the bolt fastening portion 34 from a plurality of positions surrounding the stator core 24, while being spaced apart from the projecting end of the bolt fastening portion 34 by a predetermined distance. The predetermined distance is smaller than the distance between the outer peripheral surface 24a of the stator core 24 other than the bolt fastening portion 34 and the inner wall surface 14d of the cover 14. In this way, when the stator core 24 falls in the direction T of the bolt fastening portion 34a to which the axial force of the fastening bolt 38 is applied, the tip of the projection 342a directly contacts the protruding end of the bolt fastening portion 34a, and the fall of the stator core 24 is suppressed. When the stator core 24 is inclined in the direction T toward the bolt fastening portion 34b or the bolt fastening portion 34c, which is another bolt fastening portion, the tip of the projection 342b or the projection 342c, which is another projection, directly contacts the protruding end of the bolt fastening portion 34b or the bolt fastening portion 34c, and thus the inclination of the stator core 24 is suppressed.

As described above, according to the motor 310 of the present embodiment, the tips of the plurality of protrusions 342 are in contact with any one of the plurality of bolt fastening portions 34, and therefore, the protrusions 342 suppress the inclination of the stator core 24. In this way, the

protrusions

342a, 342b, and 342c can effectively suppress the stator core 24 from falling in the direction T of the bolt fastening portion 34 to which the axial force of the fastening bolt 38 is applied.

[ example 4 ]

Fig. 8 is a diagram showing a vehicle electric motor 410 according to another embodiment of the present invention, and corresponds to fig. 3. In the present embodiment, the plurality of protrusions 442a, 442b, 442c (hereinafter, simply referred to as the protrusions 442 when the protrusions are not particularly distinguished) are provided on the inner wall surface 14d of the cover 14, and the tips of the

protrusions

442a, 442b, 442c come into contact with the intermediate position N in the circumferential direction R between the bolt fastening portions 34 of the stator core 24, whereby the stator core 24 can be prevented from falling. In the present embodiment, the distances in the circumferential direction R between the protruding

portions

442a, 442b, 442c and the bolt fastening portion 34 are longer than those in embodiments 1 to 3. However, since the plurality of protrusions 442a, 442b, 442c are provided, the present embodiment can also suppress the stator core 24 from falling down while securing a space on the lid 14 side of the stator core 24.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be applied to other embodiments.

For example, although three bolt fastening portions 34 are provided at equal intervals of 120 ° on the outer peripheral surface 24a of the stator core 24 in the foregoing embodiments 1 to 4, for example, two or five bolt fastening portions 34 may be provided at unequal intervals. Even in these cases, for example, it is possible to effectively suppress the stator core 24 from falling down in the direction T from the center axis CL toward the bolt fastening portions 34 by providing the lid 14 with the convex portions as in embodiments 1 to 4.

In embodiment 1, four protrusions 42 are provided on the inner wall surface 14d of the lid 14, but at least two protrusions may be provided, and six or nine protrusions may be provided.

In embodiments 1 to 4, any one of the above-described convex portions 42a to 42d, convex portions 242a to 242c, convex portions 243a to 243c, convex portions 342a to 342c, and convex portions 442a to 442c may be provided in combination with other portions. For example, in embodiment 1, instead of the convex portion 42a, the

convex portions

242a and 243a shown in fig. 5, the convex portion 342a shown in fig. 6, or 442a shown in fig. 8 may be provided. For example, in embodiment 1,

convex portions

242b and 243b may be provided instead of convex portion 42b, convex portion 342c may be provided instead of convex portion 42c, and convex portion 442c may be provided instead of convex portion 42 d. Further, although in the foregoing embodiments 1 to 4, the stator core 24 is fastened to the bottom portion 16b of the housing 16 by the fastening bolts 38, it may be fastened to the bottom portion 14b of the housing cover 14. In this case, the convex portion is provided so as to protrude from the inner wall surface 16d of the housing 16, and the stator core positioning portion 44 is provided so as to protrude from the inner wall surface 14d of the housing cover 14.

The above description is merely an embodiment, and the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art.

Description of the symbols

10. 210, 310, 410: motor (Motor for vehicle)

12: rotor

12 a: peripheral surface

14: lid (casing cover)

14 a: outer peripheral wall

14 d: inner wall surface

16: shell body

16 a: outer peripheral wall

16 b: bottom part

24: stator core

24 a: peripheral surface

24 b: one end part

24 c: the other end part

32: laminated steel sheet

34: bolt fastening part

38: fastening bolt

42. 242, 243, 342, 442: convex part

CL: central axis

M1, M2: angular range

N: an intermediate position.

Claims

1. An electric motor (10; 210; 310; 410) for a vehicle, comprising:

a cylindrical stator core (24) formed by laminating a plurality of laminated steel plates (32);

a bottomed cylindrical case (16) having an outer peripheral wall (16a) and accommodating one end portion (24b) of the stator core (24) in an axial direction of the stator core (24);

a bottomed cylindrical case cover (14) that has an outer peripheral wall (14a), that houses the other end (24c) of the stator core (24) in the axial direction, and that is fixed to the case (16);

a rotor (12) supported within the stator core (24) so as to be rotatable about a center axis (CL) of the stator core (24),

the vehicle motor (10; 210; 310; 410) is characterized in that,

the stator core (24) has a plurality of bolt fastening portions (34), the bolt fastening portions (34) are respectively provided so as to protrude outward in the radial direction of the stator core (24) at a plurality of positions in the outer peripheral surface (24a) of the stator core (24) that are spaced apart from each other in the circumferential direction (R), and are penetrated in the axial direction by fastening bolts (38) that fasten the stator core (24) to the bottom portion (16b) of either one (16) of the housing (16) and the housing cover (14),

the other (14) of the housing (16) and the housing cover (14) has a plurality of protrusions (42; 242, 243; 342; 442), and the plurality of protrusions (42; 242, 243; 342; 442) are provided so as to protrude toward the stator core (24) from a plurality of positions on the inner wall surface (14d) of the other (14) that surround the stator core (24), and suppress the stator core (24) from falling in the direction (T) from the center axis (CL) toward the bolt fastening section (34).

2. The vehicular electric motor (10; 210) according to claim 1,

the convex portion (42; 242, 243) is provided on an inner wall surface (14d) of the other one (14) of the housing (16) and the housing cover (14) within an angular range (M1) in which the angular range (M1) is adjacent to the bolt fastening portion (34) among angular ranges obtained by trisecting an interval between two adjacent bolt fastening portions (34) among the plurality of bolt fastening portions (34) in the circumferential direction (R).

3. The vehicular electric motor (10; 210; 310) according to claim 1 or 2,

the plurality of projections (42; 242, 243; 342) are provided at positions where the tips of the plurality of projections (42; 242, 243; 342) contact with two adjacent bolt fastening portions (34) of the plurality of bolt fastening portions (34) at positions closer to the bolt fastening portions (34) than the intermediate position (N) in the circumferential direction (R).

4. The vehicular electric motor (10; 210; 310) according to any one of claims 1 to 3,

at least one of the convex portions (42; 242, 243; 342) that suppresses the stator core (24) from falling in one direction is provided in each of a plurality of directions (T) from the center axis (CL) toward the plurality of bolt fastening portions (34).

5. The vehicular electric motor (210) according to any one of claims 1 to 4,

the pair of protruding portions (242, 243) are provided so as to protrude from the inner wall surface (14d) of the other (14) of the housing (16) and the housing cover (14) so as to sandwich the bolt fastening portion (34) from both sides in the circumferential direction (R), and the pair of protruding portions (242, 243) are provided at positions that are symmetrical to each other in the circumferential direction (R) with respect to the bolt fastening portion (34).

6. The vehicular electric motor (210) according to any one of claims 1 to 5,

the pair of protruding portions (242, 243) are provided so as to protrude from the inner wall surface (14d) of the other of the housing (16) and the housing cover (14) that faces the outer peripheral surface (24a) of the stator core (24) between two adjacent bolt fastening portions (34) of the plurality of bolt fastening portions (34), and are provided at positions that are symmetrical to each other with respect to a line that connects the center axis (CL) and an intermediate position (N) in the circumferential direction (R) between the two adjacent bolt fastening portions (34).

7. The vehicular electric motor (310) according to any one of claims 1 to 4,

the plurality of protruding portions (342) suppress the falling of the stator core (24) by the tip ends of the plurality of protruding portions (342) coming into contact with any one of the plurality of bolt fastening portions (34).

8. The vehicular electric motor (10; 210; 310) according to any one of claims 1 to 7,

the plurality of protrusions (42; 242, 243; 342) include at least two protrusions (42; 242, 243; 342) each arranged so as to be adjacent to a corresponding one of the plurality of bolt-fastening portions (34),

the distance in the circumferential direction (R) between each of the at least two projections (42; 242, 243; 342) and the corresponding one of the bolt-fastening portions (34) is set to a value equal to or less than one third of the angular interval between the corresponding one of the bolt-fastening portions (34) and the other bolt-fastening portion (34) that are adjacent to each other in the circumferential direction (R).

9. The vehicular electric motor (10; 210; 310; 410) according to any one of claims 1 to 8,

one (16) of the housing (16) and the housing cover (14) is the housing (16), and the other (14) of the housing (16) and the housing cover (14) is the housing cover (14).